Dynamo-electric machinery.



0. A. PARSONS L A. H. LAW.

DYNAMO ELECTRIC MACHINERY.

ABPLIO/ATION FILED JULY 9, 1.909.

Patented Apr. 2, 1912.

4 SHEETS-SHEET l.

C. A. PARSONS L A. H. LAW.

DYNAMO ELECTRIC MACHINERY. APPLIVOATION FILED JULY 9,1909.

Patentgd Apr. 2, 191.2.

4 SHEETS'-SIBET 2.

Arr/i A mpc. (7M "R f C. A.PARSONS a A. H. LAWe DYNAMO ELECTRICMACHINERY. APPLICATION FILED JULY 9, 1909.

1,022,255. y Patented Apr. 2, 1912.

4 SHHETB-SVHEBT 3,

DYNAMO ELECTRIC AAAAAAA Y.

IIIIIIIIIIIIIIIIIIIIIIIIII 9. v 41,022,255l Patented Apr. 2, 1912.

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' lines of torce causing` Self induction UNITED STATES PATENT OFFICE.

CHARLES ALGER-NON PARSONS AND ALEXANDER HElRTL" LWN, GF NEWGASTLEUFONTYNE, ENGLAND; SAID LAW ASSIGNAGR T0 SAID PARSONS.

DYNAMO-ELETRIC MACHINERY. L

To all whom it may concern.' y

lle itlnioun that we, (`ii.\unns Ail-(numeri Pinson; andi-iiilicxixnici: llnniiv Luv, ,aubjects oi the lingY of Great Britainand -lreland` residing at llealon lVoiliS, Newcastleuponffyne, in thecounty of Northuinheiland7 llngland, have invented certain new anduseful linproveinents in and Relating to Dynauio-'lllectric Machinery.,of which the following is a specification.

This invention relates to dynamo electric machinery and more eslieciallyto the arnia-` tui-es` oi' rotatingparte carrying conductors. t is alsoapplicable to stationary parte ot' alternatoie4 oi any electriiL-alWinding in which it is desirable to reduce the sell inn duction as muchaspossihle and which at the saine time has to he Secured Strongl fagainst mechanical forces.

ln the direct current dynamo electric inachiiies whether generators ormotora, it is well known that hettei commutation is olitained `with lesssparking' at the lirullienl hy laying the armature windings on theSin'laee ot the core rather than hy einhedilinyg; them in Slots. This isefpecially true in the ease oi high speed machines adapted lo he drivenhy steam turbines and it has hitherto heen the practice in Surface woundarmatures of this type to hold the windings, in position hy steelbinding' wirem.

The object of thisl invention is to obtain an `arrangcnrent t'orholeinel conductors whereby the eonsilructionsil advantages of' the slottype of iviniline' a re. eonihineil with the advantages as regardscommutation oiC the surface type.

- A further object is to provide means Wherehy the self induction ot'einheilded oi partially eiul'iedded conductors: may he ie duced thusreducing' the tendeney to spark at the loi'uehesy in direct currentai'niatures.

ecordin' to this invention the conductors the seit' induction o'l' theivinding'si is not appreciahly iiicieaSed 'While in many of thevniodilications proposed the conductors are made itat and thin so thatthe path for the is kept a maximum and eddy currents are kept a minimum.v

-The invention consists in an arrangement for holdingconduetore indynamo electric machinery wherein each conductor is held teSpecification of Letters Patent.

YatentedApi'. 2, 1912.

the core hy lockinga portion of the condiicous iiiipreved arrangementshereinafter described..

neierring noiv to 'the aeconiianying draw- .ings Figure l shown a plainSolid conductor locked without any special means for tighteningaccording to one foiinof the invention. liiggs. f2 to l inclusive showmodified arrangements and 'lios-ins of conductor according/to thif`invention. 8 show/S an ari'aiigeineui; oifvliolding conductora* appliedi to an arii ture in which tn-e iron is carried to a heightapproximately equal to that of the conductor. 9 and l() show in sectionand side elevation respectively a modilied conductor with slots for thepurpose of iin-,ruining` its resistance to eddy currents.

Figs. ll and l2 are similar views of a forni of ak Stranded conductor;Figs. 13, 14 and 'l5 show a construction 'aeeording to one torni thepresent invention. Fig. 16

shown in part Sectional. side elevation an arnnitiiie and tield magnetsand a modified 'lorni ol? conductor.

ln carrying` the iiiventioiirinto etlectI in the torni shown in Fig'. l,the conductors u are formed ot' a strip of copper7 aluminum 85 would hea core, hut in the case of armature.

end windings miglit he an end ring-With a dovelailv connection, theSlot, and the part oi the conductor tliei'eiin having suitableinsulation di llilith this; formation tlic strip can he slipped intoposition from one end ot the core., and does not need any specialtightening or lining ineanis.

According to a modified forni shown in Fig. 2 the conductor may be madein tivo parts c and f with enlarged sides, each' part 100 being-capableof radially entering` into the core slot, a separating piece orcalliinrstrip g, being' inserted between them for the piirpose o1keeping them Yfast in the Slot. The

calking Strip may he yolf copper or other 105 metal and may he foi-eedin radially or it. may he of insulatingy in atei'ial`r in which ease onecan obtain tivo eoniluctors'pei Slot. In

the form shown a metal plate h is used but this is not essential. Thecalking piece may be soldered, brazed or calked between or to` theconductors. The conductors also may 5 have projections formed .thereonat their facing sides in order that the calking strip may be driven inlongitudinally and held in place by these projections. Further ifdesired all parts may be tinned before asm 'sembly and afterward sweatedinto a solid mass.

According to a further modification for example as indicated in Figs. 3and 4: the conductors z may be held in place by means of tapered piecesof wood 'i or other material be wrapped entirely around the conductorsof any of the forms as indicated in Fig. 4 in order to prevent shortcircuiting by dirt or dust.

The wedge indicated in Figs. 3 and l may be in two tapered parts drivenin from either end. In these forms also the slot is shown slightlytapered so that the conductors can easily be pushed in from the end ofthe armature, but are tight when driven up to the top of the slot.

In carrying the invention into effect a`ccording to the modificationshown in Fig. 5, the split conductors w may be inserted radially into asuitable slot d and a wedge piece 85 /s or Wedge pieces forced in andheld in place either by calking or burring the core plates. lAccordingto the further modification shown in Fig. 6 circular slots m may be madein the core and suitable wedge pieces n inserted between a shapedconductor a acting to force it toward the sides of the slot. Fig. 7shows a somewhat similar arrangement. in which the wedging action isobtained by forming the conductors with a small semicircular groovethrough which a wire 0 whichr mav be of steel or other material, istightly drawn, thus forcing the conductors apart.

Fig. 8 shows an arrangement of holding the conductors applied to anarmature in which the iron'p is carried up to a height approximatelyequal to the conductor a. but in which it is kept well away from theconductor so as not appreciably to increase the self induction of thewindings. This construction has the advantage that the air gapreluctance in the magnetic circuit is reduced, and therefore', lessmagnetizing current is required, while at the same time the selfinduction is not appreciably increased. It

will be seen that the arrangement in Fig. 8

differs materially from the ordinary arrangement with a completely sunkconductor, since it is possible to keep the iron well away from theconductors. This has the effect as' pointed out of reducing self induceof the current.

tion, and at the same time allows of increased ventilation and moreeiiicient cooling of the conductor than can be obtained with acompletely embedded conductor. If preferred, the iron core may lonly becarried a short distance up as shown alternatively by the teeth' p1, p2and p, in the figure. Of course, teeth of only one height are use'd inany ordinary case.

By dividing the strips into two ormore pieces eddy currents are reducedto a minimum and this loss may be still further reduced by means oflongitudinal slits g cut in the projecting -portion of theconductor asshown by way of example in Figs. 9 and 10. These slits do notappreciably increase the resistance in a longitudinal direction.V

In the modifications described above a small portion of each conductoris embedded in the core. The conductor will therefore have a slightlylarger amount of self induci tion than if-placed entirely on thesurface. If desired, this extra self induction may be obviated byputting through transversely the embedded parts of the conductors atAshort intervals along the core as indicated by e in Fig. 10. This willprevent any current iowing in the portion of the conductor which isembedded in the core and t-he self induction will therefore be duesolely to the partof the conductor which is external to the core and.which must be made of sufficient cross sectional area to carry theWhole 'y It is found,'however, that without these transverse cuts theself induction of the conductor as a whole is increased to only atverysmall extent provided there is an external portion whose self inductionis small and which is either apart of or in electrical connect-ion withthe embedded part. Further if it be desired to reduce the eddy currentsin the conductors, instead of making the conductors of strips they maybe made of a suitably constructed stranded cable, (as shown for examplein Figs. 11 and l2) having an enlarged portion r, with an insulatingpiece d tting into suit-ably shaped slots or grooves c, in the core a'and tightly locked in any of the methods described above.

. Fig. 12.diagrammatically shows for clearness only one stranded cable ypassin at regular intervals external to the core. `Iiig 11 shows asection through the same except that all the conductors are assumed tobeV Vin place.' The lay of the cable should be so proportioned that eachstrand passes into the slot in the core at sutliciefntly frequentintervals to carrythe part external to the core and generally topreserve the stiffness of the cable.

The end windings of armatures may be constructed according to any ofthese modi- .fications in which case the conductors designated by a, e,or f on the drawings would be tl tl the end conductors and the groovessuch as c might be termed in end rings; but it is not essential that theend windings should be held in this manner as any other suitable meansmay be employed.

A general construction according to one term of the present invention isillustrated in Figs. 13 to 15, the latter being ot a ,larger scale thanthe other two figures. This construction shows magnet poles l and anarmature 2 into which conductors 3 ot the kindreferred to above arelocked. The drawing also shows a manner in which conductors .of thiskind can be placed in end rings; the end rings have projections 5thereon into which the lower row ot conductors 6 is locked and abovewhich is placed the upper row of conductors 7. The projections 5 extendupward to embrace the expanded parts at, the lower side of theconductors on the toplayer. A modified general arrangement is shown inFig. 16 including the magnets l as inF ig. 13 together with a core wwith projections as shown in Fie. 8, and conductors a. with internalwedges g, as shown in Fig.

ln armatures such as' those described above it will be seen that theconductors may be worked at very high current densiH ties owing to thegreat facilities for ventilation and this enables great economies insise to be effected and much larger outputs obtained at any given speed.

Ventilating ducts may be provided at short intervals in the core so thatthe air entering at one or bothends of the armature can pass radiallyoutward between the conductors and thence ont between the magnet poles.It is however preferred to line the tace ol the magnets with a suitablethin cylinder which will present a smooth sur face to the outtlowing airand allow this air -after leaving the Ventilating ducts to pass axiallyalong the armature between the conductors thus minimizing noise and atthe same time most eliiectively cooling the condoctors and the core.This cylinder may be perforated at intervals to allow a portion ot theair to escape, or the air may be supplied by tans on or external to thearmature and may pass from the Center outward or from the ends inward. Aconstruction ot this hind is also shown in Fig. 13 in which a. thincylinder 8 is provided lining the bore ot the magnets l and presenting asmooth surface to the ontfiowing air.. Ventilating ducts 9 are formed inthe core 2 and these are in communication with passages l0 ep;- tendingthroughout the length. otl the armatere.

Having now described our invention what we claim as new and desire tosecure by Letters Patent is zf l. lIn dynamo electricalmachinery, a`core with a slot, therein, the width o the slot at the periphery of thecore being less than its width nearer the conter a conductor withanenlarged side adapted at least-iin part to enter the slot; as setforth.

Y 2. In dynamo electric machinerya core with a slot therein the width ofthe slot at the periphery of the core being less than its width nearerthe center a conductor having an enlarged side adapted loosely to en-.

ter said slot and insulating nic-ans situate between the conductor andthe slot wall;

as set forth.

3. In dynamo electric'machinery a core the conductor and the slot walland wedging means for the purpose of tightening the conductor intheslot; as set forth.

In dynamo electric machinery a core, conductor radially in part embeddedin the core with transverse cuts in the embedded part; as set forth.

(i. In dynamo electric machinery acore with slots therein together withconductos in said slots said conductors having a part. which projectsradially beyond the mouth of' the slot and a part which is embedded andlooked in said core; as set fort-h.

7. An armature for dynamo electric machinery comprising in combination aslotted magnetic core and conductors :in said slots of which conductorsa part of each pro jects radially beyond the mouth of the slot anda partis embedded and locked in said core; as set forth.

8. ln dynamo electric machinery a core with slots therein a conductorarranged 'ith respect to the core to have two paths oit ditlcrentseit-induction electrically connected in parallel one path forme-dot a.part ot the conductor projecting radially beyond the month of a slot andthe other path formed of the other part ot the conductor embedded andlocked in the core;

set forth.

t). ln dynamo electric machinery a core body having a slot. thereinconductors arranged radially in part in said slot and in part radiallyprojecting therefrom together with means for separating them and wedgingthem in the slot; as set forth.

10.111 dynamo electric machinery a core a. conductor radially in partembedded in the core and in partextending beyond the same andprojections on said core extending to the same-height as the. conductorsso that the external dlameter of the core -is substantially equal tothat 4of the circle circumscribed about the conductors; las set-r forth.

ll. In dynamo electric machinery a fnachine element a conductor and alocking part on said conductor said conductor in part projectingradially from said machine element and in part embedded in said elementand locked'thcrein by said locking part; as set fort-h.

l2. In dynamo electric machinery a core a conductorfin part projectinvradially therefrom and in part embedded with

